1. Field of the Invention
The invention relates to a housing for protective air bag retaining systems having an air bag receiving generator carrier, a cover cap surrounding the generator carrier, and a safety plate securing the cover cap against unauthorized removal.
2. Description of the Related Technology
In known housings cover caps are provided with a reinforcing insert of textile net fabric. Blanks for the cover cap are prepared and sewn to form flap-like cover surfaces. The flap-like cover surfaces are then sewn to a closed strip representing the lateral border walls of the cap. The strip forms the reinforced frame of the insert. To prepare the finished cover, the reinforcing insert is first placed into a mold. The freely projecting flap parts are stabilized by pins in a center plane of the encasing mold. Following the closing of the mold, the insert is subsequently encased in plastic. The production of the known cover caps is extraordinarily involved and leads to an unacceptably high rejection rate. A number of process steps, such as cutting the net fabric parts and the strip, sewing the strip to the closed reinforcing frame and sewing the net fabric parts, are required to produce the reinforcing insert. The process steps involved result in the high rejection rate. In addition, the exact positioning of the reinforcing insert in the center plane of the mold is rather difficult to achieve. On the one hand the reinforcing insert is flexible, and on the other, elastically rigid within a wide range, thus it is difficult to hold the reinforcing insert in this position during the entire injection molding process. It is necessary to maintain the positioning of the reinforcing insert because the cover cap is exposed to view in the automotive vehicle, i.e., no marks must be visible on the surface of the reinforcing insert. However, for technical and cost reasons the encasing cannot exceed a certain predetermined thickness. The observation of these conditions cannot be adequately assured in operation, so a high rejection rate must be expected in the production of cover caps. Another essential disadvantage of known housings is that unauthorized access to the operating parts of the protective air bag retaining systems housing cannot be prevented or satisfactorily documented with an adequate degree of safety. This disadvantage results from the lack of a joint, excluding unauthorized release, located between the cover cap and the generator carrier or a safety plate mounted on the generator carrier. The joint is omitted for both material technical and design reasons, In known installations the cover cap is clipped onto the generator carrier with a spring-groove connection. The cover cap is secured against the safety plate projecting upward into the cap by a simple, immediately accessible and releasable screw joint.